Neuroendocrine adenoma of the middle ear with extension into the external auditory canal.

We report a case of middle ear adenoma (neuroendocrine adenoma of the middle ear) protruding into the external ear canal. The patient was a 65-year-old man with hearing alterations and a headache in whom an otoscopy disclosed a sessile, pea-sized, brown-reddish, focally bleeding mass located in the posterior-superior aspect of the right external auditory canal. Histopathologically, there was a neoplasm composed of closely packed, sometimes back-to-back glandular structures formed by small uniform cuboidal or cylindrical cells. Small solid islands were also present. Following the histopathologic examination, a high resolution computed tomography was performed showing an extensive osteolytic defect mostly involving the mastoid air cells of the mastoid process with a partial destruction of the middle ear cavity. This defect was filled with a mass-like lesion with the density of soft tissue which bulged to the external auditory canal. Histopathologic examination of the mass in the middle ear cavity revealed findings identical to those seen in the original biopsy, confirming diagnosis of middle ear adenoma extending into the external ear canal.